Patent Literatures 1-7 and Non Patent Literature 1 disclose a method for reducing carbon dioxide using light energy.
Patent Literature 1, Patent Literature 2 and Non Patent Literature 1 disclose a method for reducing carbon dioxide utilizing an oxide semiconductor such as titania as a photocatalyst material.
Patent Literature 3 and Patent Literature 4 disclose a technique for reducing carbon dioxide utilizing a photocatalyst material synthesized from predetermined metal and semiconductor.
Patent Literature 5 and Patent Literature 6 disclose a method for reducing carbon dioxide on a cathode electrode formed of a photocatalyst containing semiconductor and metal complex.
Patent Literature 7 discloses a method for reducing carbon dioxide efficiently on a cathode electrode by irradiating an anode electrode formed of semiconductor such as titania with light. According to Patent Literature 7, the method disclosed in Patent Literature 7 requires a solar cell.